This invention relates to shoes having replaceable inner soles, and more particularly to an open toe/open heel shoe having a structure for retaining replaceable inner soles.
Although replaceable inner soles are widely used in closed toe and closed heel shoes, they are not often used in open toe and open heel shoes. The toe and heel portions of enclosed shoes hold the replaceable inner soles in the proper position during wear. When used with open toe or open heel shoes, replaceable inner soles tend to sip out of position. This may cause discomfort for the person wearing the shoe, and may damage the inner sole itself.
Prior attempts to keep replaceable inner soles properly positioned within open toe or open heel shoes have involved attaching the inner sole to the insole with snap fasteners, screws, or tongue-and-groove straps. The manufacture of shoes having such fastening systems is difficult and possibly labor-intensive. Also, fasteners such as screws may only be used with hard materials, such as wood. These fastening systems may also be difficult for the wearer to use. For example, inner soles fastened with screws require a screwdriver to be disassembled and reassembled.
Another attempt to provide a replaceable inner sole for open toe or open heel shoes involved an interlocking pin and hole system and inflation of the inner sole with air. The air pressure tightened the inner sole around the pins and against a lip of the shoe base. One drawback associated with inflatable inner soles is that the inner sole may be punctured. In addition, an inflatable inner sole must be made of a polymeric material if it is to hold air under pressure. A sole made of such material would lack perspiration-absorbing properties unless it were covered by an absorbent material.
Other systems have been used to retain replaceable inner soles which extend over only a portion of the shoe base. These systems use projections extending from the inner sole which fit into recesses in the shoe base, or vice-versa. These systems rely on the force applied by the wearer's foot to keep the projections within the recesses. If the shoe is held upside-down, for example, the removable inner sole may fall out.
It would be desirable to provide a shoe having a replaceable inner sole and a simple system for retaining the inner sole in the proper position, regardless of whether or not the shoe is being worn. It would also be desirable that such a shoe be easily manufactured.